Enhancing polymer electrolyte membrane fuel cell performance and efficiency: Plasma-treated effects of expanded polytetrafluoroethylene in reinforced composite membranes

Reinforced composite membranes (RCMs) offer significant improvements in both performance and durability of proton exchange membrane fuel cells (PEMFCs) compared to conventional electrolyte membranes, primarily due to their enhanced dimensional stability under variable humidity conditions. However, the fabrication of RCMs often faces a critical challenge: incomplete impregnation between the hydrophobic expanded polytetrafluoroethylene (ePTFE) and the hydrophilic ionomer , which can lead to performance degradation . This study introduces Ar/O 2 plasma treatment on the surface of hydrophobic ePTFE to improve the impregnation of RCMs. By optimizing the dose of Ar/O 2 plasma, we successfully modify the surface properties of ePTFE from hydrophobic to hydrophilic. This transformation facilitates complete impregnation of the RCMs, resulting in enhanced proton conductivity and reduced hydrogen crossover. Consequently, single-cell performance of Ar/O 2 plasma-treated ePTFE-based RCMs exhibit superior performance than that of plasma-untreated PTFE-based RCMs. These findings highlight the potential of plasma treatment as an effective method to enhance the impregnation of RCM and thus overall PEMFC efficiency . • Ar/O 2 plasma treatment optimally modifies ePTFE from hydrophobic to hydrophilic. • Enhanced hydrophilicity improves ionomer impregnation in ePTFE. • Plasma-treated RCMs show higher proton conductivity and reduced hydrogen crossover. • Plasma-treated RCMs demonstrate higher performance and durability than untreated one.